1. Field of the Invention
The present invention relates to a current-mode receiving device, and more particularly to a current-mode receiving device included in a source driver and used in a display system.
2. Description of the Related Art
Generally, current-mode receiving devices (as distinguished from voltage-mode receiving devices) are used for improving the data transmission frequency, and reducing power consumption and noise. The benefits to be gained from operating with current as the signal parameter rather than voltage include higher frequency operation and wide dynamic range under low power supply voltages.
FIG. 1 is a circuit diagram showing an input terminal of a conventional data receiving device 121 and an output terminal of a conventional data transmission device 111. Referring to FIG. 1, the data transmission device 111 includes resistors Rz1 and Rz2, having a low resistance value, at its output terminal for transmitting more output signals and the data receiving device 121 includes an operational amplifier 123, having a high-impedance value between its input terminals, for receiving data transmission signals. The data transmission device 111 transmits a voltage data signal, while the receiving device 121 detects a voltage through two input terminals of the operational amplifier 123.
FIGS. 2A and 2B are voltage waveform diagrams of a high frequency signal and an irregular signal, respectively, input to the receiving device 121 of FIG. 1, and the resulting output signals from the receiving device.
Referring to FIG. 2A, in which a high frequency signal 211 is input to the data receiving device 121, the data receiving device 121 outputs a very weak signal 221. The output is the result of the inability of the data receiving device 121 to correctly detect or convert a high frequency signal.
FIG. 2B shows the case of an irregular signal 231 input to the receiving device 121. In this case, the receiving device 121 also outputs a very weak signal 241 and a circuit (not shown) receiving the output signal of the receiving device 121 cannot correctly recognize the output signal of the receiving device, resulting in the performance of an error-operation.
Since the operational amplifier 123 of the receiving device 121 is designed to only receive a voltage, the data receiving device 121 cannot correctly receive the high frequency data signal 211. This limitation makes it difficult to apply the data receiving device 121 to a large screen display system or a high-picture-quality display system. Furthermore, since the resistors in the output terminals of the data transmission device 111 have a low resistance value there is a resulting in high power consumption.